[net-next-2.6.git] / drivers / base / dma-coherent.c

/*
 * Coherent per-device memory handling.
 * Borrowed from i386
 */
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/dma-mapping.h>

struct dma_coherent_mem {
	void		*virt_base;
	u32		device_base;
	int		size;
	int		flags;
	unsigned long	*bitmap;
};

int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
				dma_addr_t device_addr, size_t size, int flags)
{
	void __iomem *mem_base = NULL;
	int pages = size >> PAGE_SHIFT;
	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);

	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
		goto out;
	if (!size)
		goto out;
	if (dev->dma_mem)
		goto out;

	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */

	mem_base = ioremap(bus_addr, size);
	if (!mem_base)
		goto out;

	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	if (!dev->dma_mem)
		goto out;
	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	if (!dev->dma_mem->bitmap)
		goto free1_out;

	dev->dma_mem->virt_base = mem_base;
	dev->dma_mem->device_base = device_addr;
	dev->dma_mem->size = pages;
	dev->dma_mem->flags = flags;

	if (flags & DMA_MEMORY_MAP)
		return DMA_MEMORY_MAP;

	return DMA_MEMORY_IO;

 free1_out:
	kfree(dev->dma_mem);
 out:
	if (mem_base)
		iounmap(mem_base);
	return 0;
}
EXPORT_SYMBOL(dma_declare_coherent_memory);

void dma_release_declared_memory(struct device *dev)
{
	struct dma_coherent_mem *mem = dev->dma_mem;

	if (!mem)
		return;
	dev->dma_mem = NULL;
	iounmap(mem->virt_base);
	kfree(mem->bitmap);
	kfree(mem);
}
EXPORT_SYMBOL(dma_release_declared_memory);

void *dma_mark_declared_memory_occupied(struct device *dev,
					dma_addr_t device_addr, size_t size)
{
	struct dma_coherent_mem *mem = dev->dma_mem;
	int pos, err;

	size += device_addr & ~PAGE_MASK;

	if (!mem)
		return ERR_PTR(-EINVAL);

	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
	if (err != 0)
		return ERR_PTR(err);
	return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

/**
 * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
 *
 * @dev:	device from which we allocate memory
 * @size:	size of requested memory area
 * @dma_handle:	This will be filled with the correct dma handle
 * @ret:	This pointer will be filled with the virtual address
 *		to allocated area.
 *
 * This function should be only called from per-arch dma_alloc_coherent()
 * to support allocation from per-device coherent memory pools.
 *
 * Returns 0 if dma_alloc_coherent should continue with allocating from
 * generic memory areas, or !0 if dma_alloc_coherent should return @ret.
 */
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
				       dma_addr_t *dma_handle, void **ret)
{
	struct dma_coherent_mem *mem;
	int order = get_order(size);
	int pageno;

	if (!dev)
		return 0;
	mem = dev->dma_mem;
	if (!mem)
		return 0;

	*ret = NULL;

	if (unlikely(size > (mem->size << PAGE_SHIFT)))
		goto err;

	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
	if (unlikely(pageno < 0))
		goto err;

	/*
	 * Memory was found in the per-device area.
	 */
	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
	*ret = mem->virt_base + (pageno << PAGE_SHIFT);
	memset(*ret, 0, size);

	return 1;

err:
	/*
	 * In the case where the allocation can not be satisfied from the
	 * per-device area, try to fall back to generic memory if the
	 * constraints allow it.
	 */
	return mem->flags & DMA_MEMORY_EXCLUSIVE;
}
EXPORT_SYMBOL(dma_alloc_from_coherent);

/**
 * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
 * @dev:	device from which the memory was allocated
 * @order:	the order of pages allocated
 * @vaddr:	virtual address of allocated pages
 *
 * This checks whether the memory was allocated from the per-device
 * coherent memory pool and if so, releases that memory.
 *
 * Returns 1 if we correctly released the memory, or 0 if
 * dma_release_coherent() should proceed with releasing memory from
 * generic pools.
 */
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;

	if (mem && vaddr >= mem->virt_base && vaddr <
		   (mem->virt_base + (mem->size << PAGE_SHIFT))) {
		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;

		bitmap_release_region(mem->bitmap, page, order);
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(dma_release_from_coherent);
Commit	Line	Data
ee7e5516 DES	1	/*
	2	* Coherent per-device memory handling.
	3	* Borrowed from i386
	4	*/
5a0e3ad6	5	#include <linux/slab.h>
ee7e5516 DES	6	#include <linux/kernel.h>
	7	#include <linux/dma-mapping.h>
	8
	9	struct dma_coherent_mem {
	10	void *virt_base;
	11	u32 device_base;
	12	int size;
	13	int flags;
	14	unsigned long *bitmap;
	15	};
	16
	17	int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
	18	dma_addr_t device_addr, size_t size, int flags)
	19	{
	20	void __iomem *mem_base = NULL;
	21	int pages = size >> PAGE_SHIFT;
	22	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
	23
	24	if ((flags & (DMA_MEMORY_MAP \| DMA_MEMORY_IO)) == 0)
	25	goto out;
	26	if (!size)
	27	goto out;
	28	if (dev->dma_mem)
	29	goto out;
	30
	31	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
	32
	33	mem_base = ioremap(bus_addr, size);
	34	if (!mem_base)
	35	goto out;
	36
	37	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	38	if (!dev->dma_mem)
	39	goto out;
	40	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	41	if (!dev->dma_mem->bitmap)
	42	goto free1_out;
	43
	44	dev->dma_mem->virt_base = mem_base;
	45	dev->dma_mem->device_base = device_addr;
	46	dev->dma_mem->size = pages;
	47	dev->dma_mem->flags = flags;
	48
	49	if (flags & DMA_MEMORY_MAP)
	50	return DMA_MEMORY_MAP;
	51
	52	return DMA_MEMORY_IO;
	53
	54	free1_out:
	55	kfree(dev->dma_mem);
	56	out:
	57	if (mem_base)
	58	iounmap(mem_base);
	59	return 0;
	60	}
	61	EXPORT_SYMBOL(dma_declare_coherent_memory);
	62
	63	void dma_release_declared_memory(struct device *dev)
	64	{
	65	struct dma_coherent_mem *mem = dev->dma_mem;
	66
	67	if (!mem)
	68	return;
	69	dev->dma_mem = NULL;
70	iounmap(mem->virt_base);
71	kfree(mem->bitmap);
72	kfree(mem);
73	}
74	EXPORT_SYMBOL(dma_release_declared_memory);
75
76	void dma_mark_declared_memory_occupied(struct device dev,
77	dma_addr_t device_addr, size_t size)
78	{
79	struct dma_coherent_mem *mem = dev->dma_mem;
80	int pos, err;
ee7e5516	81
d2dc1f4a	82	size += device_addr & ~PAGE_MASK;
ee7e5516 DES	83
	84	if (!mem)
	85	return ERR_PTR(-EINVAL);
	86
	87	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
d2dc1f4a	88	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
ee7e5516 DES	89	if (err != 0)
	90	return ERR_PTR(err);
	91	return mem->virt_base + (pos << PAGE_SHIFT);
	92	}
	93	EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
	94
b6d4f7e3	95	/**
cb3952bf	96	* dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
b6d4f7e3 DES	97	*
	98	* @dev: device from which we allocate memory
	99	* @size: size of requested memory area
	100	* @dma_handle: This will be filled with the correct dma handle
	101	* @ret: This pointer will be filled with the virtual address
0609697e	102	* to allocated area.
b6d4f7e3	103	*
cb3952bf	104	* This function should be only called from per-arch dma_alloc_coherent()
b6d4f7e3 DES	105	* to support allocation from per-device coherent memory pools.
	106	*
	107	* Returns 0 if dma_alloc_coherent should continue with allocating from
cb3952bf	108	* generic memory areas, or !0 if dma_alloc_coherent should return @ret.
b6d4f7e3	109	*/
ee7e5516 DES	110	int dma_alloc_from_coherent(struct device *dev, ssize_t size,
	111	dma_addr_t dma_handle, void *ret)
	112	{
eccd83e1	113	struct dma_coherent_mem *mem;
ee7e5516	114	int order = get_order(size);
eccd83e1	115	int pageno;
ee7e5516	116
eccd83e1 AM	117	if (!dev)
	118	return 0;
	119	mem = dev->dma_mem;
	120	if (!mem)
	121	return 0;
0609697e PM	122
	123	*ret = NULL;
	124
cdf57cab	125	if (unlikely(size > (mem->size << PAGE_SHIFT)))
0609697e	126	goto err;
eccd83e1 AM	127
eccd83e1 AM	128	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
0609697e PM	129	if (unlikely(pageno < 0))
	130	goto err;
	131
	132	/*
	133	* Memory was found in the per-device area.
	134	*/
	135	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
	136	*ret = mem->virt_base + (pageno << PAGE_SHIFT);
	137	memset(*ret, 0, size);
	138
eccd83e1	139	return 1;
0609697e PM	140
	141	err:
	142	/*
	143	* In the case where the allocation can not be satisfied from the
	144	* per-device area, try to fall back to generic memory if the
	145	* constraints allow it.
	146	*/
	147	return mem->flags & DMA_MEMORY_EXCLUSIVE;
ee7e5516	148	}
a38409fb	149	EXPORT_SYMBOL(dma_alloc_from_coherent);
ee7e5516	150
b6d4f7e3	151	/**
cb3952bf	152	* dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
b6d4f7e3 DES	153	* @dev: device from which the memory was allocated
	154	* @order: the order of pages allocated
	155	* @vaddr: virtual address of allocated pages
	156	*
	157	* This checks whether the memory was allocated from the per-device
	158	* coherent memory pool and if so, releases that memory.
	159	*
	160	* Returns 1 if we correctly released the memory, or 0 if
cb3952bf	161	* dma_release_coherent() should proceed with releasing memory from
b6d4f7e3 DES	162	* generic pools.
b6d4f7e3 DES	163	*/
ee7e5516 DES	164	int dma_release_from_coherent(struct device dev, int order, void vaddr)
	165	{
	166	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	167
	168	if (mem && vaddr >= mem->virt_base && vaddr <
	169	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
	170	int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
	171
	172	bitmap_release_region(mem->bitmap, page, order);
	173	return 1;
	174	}
	175	return 0;
	176	}
a38409fb	177	EXPORT_SYMBOL(dma_release_from_coherent);